With the process of High-Pressure-Nitriding nitrogen can be dissolved in the surface of stainless steels. The components are treated with a pressure up to 3000 mbar and a temperature of 1050° up to 1150°C followed by a fast quenching in order to avoid the precipitation of nitrides.

The diffusion of nitrogen-atoms increases the hardness and corrosion resistance. Depending on the alloying content of the steel and the amount of diffused nitrogen, an austenitic or martensitic surface-structure will be reached.

CrMo- and CrMnMo alloyed steels are recommended for this process.

This particular process is used for medical engineering, stainless steel bearings, pumps and compressors etc.